NPS drawings The giant crater (“caldera”) formed by the eruption and collapse of Yellowstone Supervolcano 640,000 years ago dwarfs the crater on top of Mt. St. Helens and the caldera of Mt. Mazama
drawings of The giant crater (“caldera”) formed by the eruption and collapse of Yellowstone Supervolcano 640,000 years ago dwarfs the crater on top of Mt. St. Helens and the caldera of Mt. Mazama